In situ synthesis of N-doped TiO2 on Ti3C2 MXene with enhanced photocatalytic activity in the selective reduction of nitrate to N2. Issue 6 (9th February 2022)

• Record Type: Journal Article
• Authors: Zheng, Rui; Li, Chunhu; Huang, Kelei; Guan, Ying; Wang, Wentai; Wang, Liang; Bian, Junjie; Meng, Xiangchao
• Is Part Of: Inorganic chemistry frontiers. Volume 9:Issue 6(2022)
• Page Start: 1195
• Page End: 1207
• Publication Date: 2022-02-09
• Subjects: Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1qi01614h
• Languages: English
• ISSNs: 2052-1553

Abstract

Abstract : Photocatalysis exhibits promise in the reduction of nitrates into harmless dinitrogen. Abstract : Photocatalysis exhibits promise in the reduction of nitrates into harmless dinitrogen. Herein, the synthesis of N-doped TiO2 /Ti3 C2 at a low calcination temperature using NH4 Cl and Ti3 C2 was reported for the first time. Cationic NH4 + was intercalated into the interlayers of Ti3 C2 and NH4 Cl was self-assembled on the surface of Ti3 C2 . N-doped TiO2 /Ti3 C2 was in situ synthesized by one-step calcining the Ti3 C2 MXene and NH4 Cl mixture. The as-prepared composite exhibited excellent activity in the photocatalytic reduction of nitrate. As characterized, the N-dopant added an impurity energy level within the band gap of TiO2, which was favourable for improving the light absorption ability. Meanwhile, the metallic nature of Ti3 C2 with a layered structure accelerated the charge transfer between N-TiO2 and Ti3 C2, and further facilitated the separation of photogenerated charge carriers. Moreover, the addition of formic acid in the solution not only acted as a hole scavenger to produce the reducing agent ·CO2 −, but also provided extra reactive electrons by generating the charge-transfer-complex between N-TiO2 and formic acid, which greatly promoted the photocatalytic reduction of nitrate. Notably, NO3 − with Lewis basic property was easily adsorbed onto the Lewis acid sites on the surface of N-doped TiO2 /Ti3 C2 by the electrostatic force. All the above-mentioned superiorities contributed to the greatly enhanced photocatalytic activity of the N-doped TiO2 /Ti3 C2 composite in the reduction of nitrate. The mechanism has also been proposed based on the testing results.